U.S. Pat. No. 3,519,101 granted Jan. 10, 1968 to J. E. Sieffert discloses a construction elevator system which includes a bedplate carrying an electric motor and traction and deflection sheaves for driving elevator car and counterweight cables. Below the bedplate are the car and counterweight assemblies which are driven by the motor and sheaves. The system is used to payout hoistway cable as the building is being erected. Spools of elevator cable, including the hoist and governor ropes, are disposed on the top of the elevator car and cable being fed off of the spools is clamped to the top cross beams of the car. Cables run from the clamps to the traction sheave and therefrom to the counterweight. The construction elevator system is positioned on one of the higher levels of the hoistway during erection of the building. The elevator car is then run up and down in the hoistway to transport men and materials used in construction of the floors below the bedplate portion of the assembly. Meanwhile, erection of floors above the bedplate is continued. Guide rails are installed above the bedplate in the hoistway as the number of floors above the bedplate increases. After a predetermined number of floors has been built above the bedplate, for example six floors, the car is lifted to its highest possible height while the counterweight is lowered to its buffer. The car is then shackled to the bedplate and the bedplate is disconnected from the building beams. Before the car is lifted and shackled to the bedplate, the governor will be lifted to the new upper location and secured thereat. The governor cable will be unclamped and fed off of one of the cable spools on the car. The hoist cables are disconnected from the lowered counterweight. The bedplate and car are then connected to a crane cable and are craned up to the new level by the construction site crane. Once the bedplate is secured in its new location, it is disconnected from the crane cable and the additional hoisting cables are unwound from the spools on the car and are paid down to the counterweight for reattachment thereto. To accomplish this reattachment, the cables are clamped together and the clamp is connected to a hemp rope which is winched or otherwise snubbed to the bedplate. The cable clamps on the car are then released in a preset sequence, and some of the clamps are used as friction clamps as the cables are fed out to the counterweight. When a two to one roping arrangement is used, special measures must be taken to prevent the counterweight dead-end hitch from falling into the hoistway. It will be appreciated that the aforesaid construction elevator is time consuming due to all of the clamps that have to be changed, and does not include a safety brake for emergency application during payout of additional cable. Additionally, much stress is put on the car due to the weight of the cable spools mounted thereon.